Clean Methods for Diesel Generator Lubrication System

The lubrication system of a diesel generator is a key component that ensures the efficient and stable operation of the engine. Its main task is to supply clean, temperature-appropriate oil to the engine's friction surfaces, reducing friction losses and wear on parts while carrying away heat and debris. A well-functioning lubrication system can extend the engine's life, improve fuel efficiency, and ensure the reliability and performance of the diesel generator under various operating conditions.

Components of the Lubrication System

The lubrication system of a diesel generator is made up of several crucial parts, including:

Oil Strainer: This filters out impurities from the oil, protecting subsequent system components from contamination.
Oil Pump: It provides the necessary oil pressure to deliver lubricating oil to various engine points.
Oil Filter: It further filters out particles and contaminants, ensuring that only clean oil reaches the engine.
Oil Cooler: Used to lower the oil temperature, preventing overheating and oil degradation.
Oil Pressure Relief Valve: This regulates system pressure, preventing damage from excessive oil pressure.
Oil Sump and Pipes: These store and transport the oil, ensuring it reaches all lubrication points in the engine.

Functions of the Lubrication System

The primary function of the lubrication system is to provide sufficient oil to the moving parts of the engine, reducing friction and wear to ensure smooth operation. The system achieves lubrication through two methods.
Pressure Lubrication: The oil pump pressurizes the oil and delivers it to key engine components such as the crankshaft and connecting rods.
Splash Lubrication: Engine movement causes the oil to splash onto other friction surfaces, further enhancing lubrication.
Besides reducing wear, the lubricating oil also helps clean engine parts by carrying away heat and removing metal particles caused by wear, ensuring the engine continues to run efficiently.

Cleaning and Maintenance of the Lubrication System

Over time, impurities in the lubricating oil can accumulate in the system's pipes and components, affecting its normal operation. Deposits in the oil cooler can increase heat transfer resistance, reducing cooling efficiency and potentially causing engine overheating. Therefore, regular cleaning of the lubrication system is essential. Lubrication system cleaning is generally carried out when changing the oil, using two main methods.

1. Disassembly Cleaning

Components like the oil strainer, pipes, filters, and oil cooler are removed and soaked in kerosene or diesel for cleaning. Afterward, they are blown dry with compressed air, wiped clean, and reassembled to ensure clear oil passage.

2. Circulation Cleaning

Suitable for small to medium-sized diesel engines, this method involves draining old oil from the crankcase and oil filters, then adding a mixture of 15-20% diesel or kerosene and 80-85% oil. The engine is then run at idle speed (about 700 rpm) for 5-8 minutes. Afterward, the mixture is drained, and the oil filters and cooler are cleaned. Finally, fresh oil is added, and the engine is run at idle for 2-3 minutes to ensure normal operation.
After cleaning, it's important to check the oil pressure. If abnormal, the engine should be stopped for inspection and troubleshooting. Additionally, the oil level in the sump should be checked 30 minutes after shutdown to ensure it is at the standard level before resuming normal operation.

Dealing with Asphalt and Tar Deposits

Oil channels in high-temperature engine areas, such as the cylinder block, crankshaft, and connecting rods, may accumulate asphalt and tar deposits that are difficult to remove using standard methods. In such cases, an alkaline water-based metal cleaner is typically used, with a pH controlled between 12.5 and 13, and cleaning temperatures kept between 70-90°C. Components are soaked in this solution for 1-3 hours, softening the deposits before being flushed with cleaning equipment.
For disassembled components like the oil tank, pump, and filters, soaking them in gasoline for 8 hours helps soften stubborn dirt. Nylon or metal brushes can be used to clean the surfaces, while pipe brushes are employed to clean the internal dirt, ensuring all passages are clear.

Post-Cleaning Considerations

After cleaning and refilling the system with the correct grade of lubricating oil, the crankshaft should be turned to allow the oil to flow through the system. The engine should be idled for 2-3 minutes to confirm proper oil circulation. It's essential to check that the oil pressure remains within the normal range; if any anomalies are detected, the engine should be stopped for further inspection. The oil level in the sump should be checked again 30 minutes after cleaning to ensure it meets the standard level.

Conclusion

As a vital part of the diesel generator, regular cleaning and maintenance of the lubrication system are crucial. By removing impurities and deposits from the system, proper maintenance ensures clean and efficient oil flow, which extends engine life and improves the generator's operational efficiency. In practical use, correct maintenance methods not only help keep the equipment running smoothly but also reduce failure rates, improving overall reliability and cost-effectiveness.